drm/komeda: Add debugfs node to control error verbosity

Named 'err_verbosity', currently with only 1 active bit in that
replicates the existing level - print error events once per flip.
Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191107114155.54307-2-mihail.atanassov@arm.com

drivers/gpu/drm/arm/display/komeda/komeda_dev.c

@@ -58,6 +58,8 @@ static void komeda_debugfs_init(struct komeda_dev *mdev)
 	mdev->debugfs_root = debugfs_create_dir("komeda", NULL);
 	debugfs_create_file("register", 0444, mdev->debugfs_root,
 			    mdev, &komeda_register_fops);
+	debugfs_create_x16("err_verbosity", 0664, mdev->debugfs_root,
+			   &mdev->err_verbosity);
 }
 #endif
 
@@ -273,6 +275,8 @@ struct komeda_dev *komeda_dev_create(struct device *dev)
 		goto err_cleanup;
 	}
 
+	mdev->err_verbosity = KOMEDA_DEV_PRINT_ERR_EVENTS;
+
 #ifdef CONFIG_DEBUG_FS
 	komeda_debugfs_init(mdev);
 #endif

drivers/gpu/drm/arm/display/komeda/komeda_dev.h

@@ -202,6 +202,14 @@ struct komeda_dev {
 
 	/** @debugfs_root: root directory of komeda debugfs */
 	struct dentry *debugfs_root;
+	/**
+	 * @err_verbosity: bitmask for how much extra info to print on error
+	 *
+	 * See KOMEDA_DEV_* macros for details.
+	 */
+	u16 err_verbosity;
+	/* Print a single line per error per frame with error events. */
+#define KOMEDA_DEV_PRINT_ERR_EVENTS BIT(0)
 };
 
 static inline bool
@@ -219,9 +227,11 @@ void komeda_dev_destroy(struct komeda_dev *mdev);
 struct komeda_dev *dev_to_mdev(struct device *dev);
 
 #ifdef CONFIG_DRM_KOMEDA_ERROR_PRINT
-void komeda_print_events(struct komeda_events *evts);
+void komeda_print_events(struct komeda_events *evts, struct drm_device *dev);
 #else
-static inline void komeda_print_events(struct komeda_events *evts) {}
+static inline void komeda_print_events(struct komeda_events *evts,
+				       struct drm_device *dev)
+{}
 #endif
 
 int komeda_dev_resume(struct komeda_dev *mdev);

drivers/gpu/drm/arm/display/komeda/komeda_event.c

@@ -107,10 +107,12 @@ static bool is_new_frame(struct komeda_events *a)
 	       (KOMEDA_EVENT_FLIP | KOMEDA_EVENT_EOW);
 }
 
-void komeda_print_events(struct komeda_events *evts)
+void komeda_print_events(struct komeda_events *evts, struct drm_device *dev)
 {
-	u64 print_evts = KOMEDA_ERR_EVENTS;
+	u64 print_evts = 0;
 	static bool en_print = true;
+	struct komeda_dev *mdev = dev->dev_private;
+	u16 const err_verbosity = mdev->err_verbosity;
 
 	/* reduce the same msg print, only print the first evt for one frame */
 	if (evts->global || is_new_frame(evts))
@@ -118,6 +120,9 @@ void komeda_print_events(struct komeda_events *evts)
 	if (!en_print)
 		return;
 
+	if (err_verbosity & KOMEDA_DEV_PRINT_ERR_EVENTS)
+		print_evts |= KOMEDA_ERR_EVENTS;
+
 	if ((evts->global | evts->pipes[0] | evts->pipes[1]) & print_evts) {
 		char msg[256];
 		struct komeda_str str;

drivers/gpu/drm/arm/display/komeda/komeda_kms.c

@@ -48,7 +48,7 @@ static irqreturn_t komeda_kms_irq_handler(int irq, void *data)
 	memset(&evts, 0, sizeof(evts));
 	status = mdev->funcs->irq_handler(mdev, &evts);
 
-	komeda_print_events(&evts);
+	komeda_print_events(&evts, drm);
 
 	/* Notify the crtc to handle the events */
 	for (i = 0; i < kms->n_crtcs; i++)